Samar Alharbi1,2, Zareen Ahmad1,2, Arthur A Bookman1,2, Zahi Touma1,2, Jorge Sanchez-Guerrero1,2, Nicholas Mitsakakis1,2, Sindhu R Johnson3,4. 1. From the Toronto Scleroderma Program, Division of Rheumatology, Toronto Western Hospital, University Health Network; Division of Rheumatology, Mount Sinai Hospital, University of Toronto; Institute of Health Policy, Management and Evaluation, and Toronto Health Economics and Technology Assessment Collaborative, University of Toronto, Toronto, Ontario, Canada; Taibah University, Medina, Saudi Arabia. 2. S. Alharbi, MD, Toronto Scleroderma Program, Division of Rheumatology, Toronto Western Hospital, University Health Network, and Division of Rheumatology, Mount Sinai Hospital, University of Toronto, and Taibah University; Z. Ahmad, MD, Division of Rheumatology, Mount Sinai Hospital, University of Toronto; A.A. Bookman, MD, Toronto Scleroderma Program, Division of Rheumatology, Toronto Western Hospital, University Health Network; Z. Touma, MD, PhD, Toronto Scleroderma Program, Division of Rheumatology, Toronto Western Hospital, University Health Network, and Institute of Health Policy, Management and Evaluation, University of Toronto; J. Sanchez-Guerrero, MD, MSc, Toronto Scleroderma Program, Division of Rheumatology, Toronto Western Hospital, University Health Network, and Division of Rheumatology, Mount Sinai Hospital, University of Toronto; N. Mitsakakis, PhD, Institute of Health Policy, Management and Evaluation, and Toronto Health Economics and Technology Assessment Collaborative, University of Toronto; S.R. Johnson, MD, PhD, Toronto Scleroderma Program, Division of Rheumatology, Toronto Western Hospital, University Health Network, University of Toronto, and Division of Rheumatology, Mount Sinai Hospital, and Institute of Health Policy, Management and Evaluation, University of Toronto. 3. From the Toronto Scleroderma Program, Division of Rheumatology, Toronto Western Hospital, University Health Network; Division of Rheumatology, Mount Sinai Hospital, University of Toronto; Institute of Health Policy, Management and Evaluation, and Toronto Health Economics and Technology Assessment Collaborative, University of Toronto, Toronto, Ontario, Canada; Taibah University, Medina, Saudi Arabia. Sindhu.Johnson@uhn.ca. 4. S. Alharbi, MD, Toronto Scleroderma Program, Division of Rheumatology, Toronto Western Hospital, University Health Network, and Division of Rheumatology, Mount Sinai Hospital, University of Toronto, and Taibah University; Z. Ahmad, MD, Division of Rheumatology, Mount Sinai Hospital, University of Toronto; A.A. Bookman, MD, Toronto Scleroderma Program, Division of Rheumatology, Toronto Western Hospital, University Health Network; Z. Touma, MD, PhD, Toronto Scleroderma Program, Division of Rheumatology, Toronto Western Hospital, University Health Network, and Institute of Health Policy, Management and Evaluation, University of Toronto; J. Sanchez-Guerrero, MD, MSc, Toronto Scleroderma Program, Division of Rheumatology, Toronto Western Hospital, University Health Network, and Division of Rheumatology, Mount Sinai Hospital, University of Toronto; N. Mitsakakis, PhD, Institute of Health Policy, Management and Evaluation, and Toronto Health Economics and Technology Assessment Collaborative, University of Toronto; S.R. Johnson, MD, PhD, Toronto Scleroderma Program, Division of Rheumatology, Toronto Western Hospital, University Health Network, University of Toronto, and Division of Rheumatology, Mount Sinai Hospital, and Institute of Health Policy, Management and Evaluation, University of Toronto. Sindhu.Johnson@uhn.ca.
Abstract
OBJECTIVE: Systemic sclerosis (SSc) may overlap with systemic lupus erythematous (SLE). Little is known about the epidemiology, clinical characteristics, and survival of SSc-SLE overlap. We evaluated the prevalence of SSc-SLE overlap and differences in SSc characteristics, and compared survival with SSc without SLE. METHODS: A cohort study was conducted including subjects who fulfilled the American College of Rheumatology (ACR)/European League Against Rheumatism classification criteria for SSc and/or the ACR criteria for SLE. The primary outcome was time from diagnosis to all-cause mortality. Survival was evaluated using Kaplan-Meier and Cox proportional hazard models. RESULTS: We identified 1252 subjects (SSc: n = 1166, SSc-SLE: n = 86) with an SSc-SLE prevalence of 6.8%. Those with SSc-SLE were younger at diagnosis (37.9 yrs vs 47.9 yrs, p < 0.001), more frequently East Asian (5.5% vs 20%) or South Asian (5.1% vs 12%), had lupus anticoagulant (6% vs 0.3%, p < 0.001), anticardiolipin antibody (6% vs 0.9%, p < 0.001), and pulmonary arterial hypertension (PAH; 52% vs 31%, p < 0.001). Those with SSc-SLE less frequently had calcinosis (13% vs 27%, p = 0.007), telangiectasia (49% vs 75%, p < 0.001), and diffuse subtype (12% vs 35%, p < 0.001). There were no significant differences in the occurrence of renal crisis (7% vs 7%), interstitial lung disease (ILD; 41% vs 34%), and digital ulcers (38% vs 32%). Those with SSc-SLE had better median survival time (26.1 vs 22.4 yrs), but this was not statistically significant (log-rank p = 0.06). Female sex and diffuse subtype attenuated survival differences between groups (HR 1.07, 95% CI 0.67-1.67). CONCLUSION: Patients with SSc-SLE are younger at diagnosis, more frequently have PAH, and less frequently have cutaneous manifestations of SSc. They should be monitored for ILD, renal crisis, and digital ulcers.
OBJECTIVE: Systemic sclerosis (SSc) may overlap with systemic lupus erythematous (SLE). Little is known about the epidemiology, clinical characteristics, and survival of SSc-SLE overlap. We evaluated the prevalence of SSc-SLE overlap and differences in SSc characteristics, and compared survival with SSc without SLE. METHODS: A cohort study was conducted including subjects who fulfilled the American College of Rheumatology (ACR)/European League Against Rheumatism classification criteria for SSc and/or the ACR criteria for SLE. The primary outcome was time from diagnosis to all-cause mortality. Survival was evaluated using Kaplan-Meier and Cox proportional hazard models. RESULTS: We identified 1252 subjects (SSc: n = 1166, SSc-SLE: n = 86) with an SSc-SLE prevalence of 6.8%. Those with SSc-SLE were younger at diagnosis (37.9 yrs vs 47.9 yrs, p < 0.001), more frequently East Asian (5.5% vs 20%) or South Asian (5.1% vs 12%), had lupus anticoagulant (6% vs 0.3%, p < 0.001), anticardiolipin antibody (6% vs 0.9%, p < 0.001), and pulmonary arterial hypertension (PAH; 52% vs 31%, p < 0.001). Those with SSc-SLE less frequently had calcinosis (13% vs 27%, p = 0.007), telangiectasia (49% vs 75%, p < 0.001), and diffuse subtype (12% vs 35%, p < 0.001). There were no significant differences in the occurrence of renal crisis (7% vs 7%), interstitial lung disease (ILD; 41% vs 34%), and digital ulcers (38% vs 32%). Those with SSc-SLE had better median survival time (26.1 vs 22.4 yrs), but this was not statistically significant (log-rank p = 0.06). Female sex and diffuse subtype attenuated survival differences between groups (HR 1.07, 95% CI 0.67-1.67). CONCLUSION:Patients with SSc-SLE are younger at diagnosis, more frequently have PAH, and less frequently have cutaneous manifestations of SSc. They should be monitored for ILD, renal crisis, and digital ulcers.